docs: def _hole_start(self, position, ignore=None):
          """
          Retrieves the start of hole index from position.
          :param position:
          :type position:
          :param ignore:
          :type ignore:
          :return:
          :rtype:
          """
          for lindex in reversed(range(0, position)):
              for starting in self.starting(lindex):
                  if not ignore or not ignore(starting):
                      return lindex
          return 0